diff --git a/win/rfb_win32/ToolBar.h b/win/rfb_win32/ToolBar.h
index 2242c2a..f256c99 100644
--- a/win/rfb_win32/ToolBar.h
+++ b/win/rfb_win32/ToolBar.h
@@ -112,6 +112,10 @@
       // getHeight() returns the toolbar window height.
       int getHeight();
 
+      // getTotalWidth() returns the total size of all buttons and 
+      // separators in the toolbar.
+      int getTotalWidth();
+
       // show() displays the toolbar window.
       void show();